This invention relates to the field of power transmission devices and in particular power transmission devices in automobiles used to disengage the motor from the transmission in order to effect a gear change.
In the past, power transmission devices have included friction clutches in which two rotating plates are rotated together when frictionally engaged. The plates were separated from each other in order to disengage the motor from the transmission and effect a gear change. Such friction clutches suffer from several disadvantages such as poor control over the re-engagement of the motor, an abrupt re-engagement, and excessive wear due to the interaction of the rotating plates.
Furthermore, the friction clutches do not provide for a means of increasing the rate of rotation of the output shaft to the transmission above the rate of rotation of the input shaft from the car's motor.